Wien Energie has commissioned its first redox-flow battery storage pilot at the Donaustadt power plant site in Vienna, adding a new technology to the utility’s growing storage portfolio. The system stores surplus solar power from the adjacent PV plant for later use and will help the company assess what role redox-flow technology can play in its future storage mix.
A 230 kWh vanadium flow system
The pilot has 80 kW of power output and 230 kWh of capacity, making it the largest operational storage unit of its kind in Austria, according to Wien Energie. The system is housed in a 25-tonne 20-foot container, with energy stored modularly in two tanks of liquid electrolyte.
The battery comes from European storage manufacturer Invinity Energy Systems in cooperation with Austrian company Wildburger Power & Storage. Invinity CEO Jonathan Marren said the project demonstrates the strengths of vanadium redox-flow batteries in practical operation. Invinity co-founder Dr Josef Wildburger called the deployment of its series-ready long-duration storage in Austria with a leading utility an important step.
Why vanadium redox flow
Unlike lithium-ion batteries, redox-flow batteries store energy not in the cells but in an electrolyte that is mostly water-based, non-flammable and held in separate tanks. The electrolyte degrades only slightly during charging and discharging and can be used for many years. The systems are designed for a high number of cycles and long operating life. The vanadium is not consumed and can be recovered and reused at end of life. Wien Energie says redox-flow storage is suited to storing larger amounts of energy.
Part of a wider storage build-out
Wien Energie’s most powerful battery storage is at Schafflerhofstraße in Vienna’s 22nd district, with 5 MW of power and 12 MWh of capacity, storing solar energy from Vienna’s largest PV plant. Further large-scale storage totalling 25 MW of power and 50 MWh of capacity is to follow by the end of this year. Austria’s largest second-life battery storage, using around 400 retired EV batteries, went into operation in summer in Rosiwalgasse in the 23rd district.
“A secure and independent energy system needs powerful storage solutions alongside renewable expansion,” said Wien Energie managing director Sascha Zabransky. He said the utility deliberately relies on different technologies ranging from storage made from used EV batteries to redox-flow systems.
The pilot is small relative to Wien Energie’s lithium-ion fleet, but it gives the utility operating data on a technology designed for longer durations and many cycles.
This article was assisted by AI analysis. Please refer to the original source for official information.